Control mechanism for push button and the like



y 30, 1957 A. G. SANGSTER 2,800,806

CONTROL MECHANISM FOR PUSH BUTTON AND THE LIKE Filed Sept. 27. 1952 28 vr 44- 54- q 30 2o 32 2 J6 4 38 l8 OG )5 IN VEN TOR.

United States Patent CONTROL MECHANISM FOR PUSH BUTTON AND vTHE LIKEArlon G. Sangster, Leominster, Mass., assignor to Arter Grinding MachineCompany, Worcester, Mass., a corporation of Massachusetts ApplicationSeptember 27, 1952, Serial No. 311,850

3 Claims. (Cl. 74-503) This invention relates to a new and improvedcontrol mechanism for push buttons and the like rectilinearly operabledevices such as start and stop buttons for the control of machinery, andone of the principal objects of the present invention resides in theprovision of an attachment which may be incorporated as a part of aconventional push 'button or the like so that the same may be operatedby an angular motion of a control rod rather by axial pushing motion onthe push button to the end that the push button or the like may be muchmore easily operated, particularly in cases where the push buttons areoperated continually and also to the end that the control of the pushbutton is made more positive.

Another object of the invention resides in the provision of thecombination of a push button and angularly movable means and mechanismconverting the same into the reciprocatory motion required for operatingthe push button, said means including a spring opposing the conventionalpush button return spring, the strength of said spring being greaterthan the strength of the push button spring, this spring thereforeovercoming the push button spring. This spring, however, has a travelonly half the length of the push button spring and therefore pushes thepush button only to a mid point, at which point both contacts are open.The device therefore functions as a spring centered normally open doublethrow switch.

A further object of the invention includes the provision of a devicehaving means for attachment to the housing of a push button or othersimilar rectilinearly movable operator element, a shell on theattachment, a handle to rotate or oscillate the shell, a cam sleeve inthe shell movable therewith, a cross pin moved rectilinearly only as thecam sleeve is moved angularly or rotatively, means to constrain thecross pin to a rectilinear path, and a plunger connected to the crosspin for operation thereby, the attachment being secured to the housingin position to cause depression of the push button upon movement of thehandle in one direction. Other objects and advantages of the inventionwill appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 isa perspective view, partly in section, illustrating the device;

Fig. 2 is a top plan view of the device; and

Fig. 3 is a vertical section therethrough.

The reference numeral indicates a bracket for the support of aconventional push button 12 having an exteriorly threaded casing 14. Thepush button 12 is provided with a return spring 16, so that when theoperator pushes down upon plunger 12, the same is automatically returnedby the spring. The plunger 12 works in the casing 14, and the latter isfixed on a machine or on the usual push button housing bracket 10. Thesepush buttons may be used for starting or stopping machinery and in manyother applications. In many instances, the push buttons have to beoperated continually so that the Opera 2,800,806 Patented July 30, 1957tors finger becomes sore and tired from the operation thereof.

The present invention comprises a nut 18 adapted to be threaded upon thethreads 14 and this nut is adapted to be firmly seated on the threads onthe push button hous ing. Secured to the nut or integral therewith thereis a central shell, sleeve or the like indicated at 20. This shell atits upper end is provided with a boss 22 into which is threaded afastener holding plate 24. A washer 26 is disposed on the top of thesleeve 20 which is closed at thisend, and forms a rotative bearing foran exterior housing 28 to which is secured a handle 30. When the handle38 is moved angularly as for instance between the o' and forwardpositions in Fig. l, the exterior housing 28 is similarly rotated. Theplate 24 holds the housing 28 to the shell20, but housing 28 isrotatable thereon.

The interior of housing 23 hasa series of longitudinal serrations 34 toreceive a mating set of serrations on the outside surface of a sleeve32. These serrations serve to lock parts 28, 32 together, so that theymove together, and they also serve the purpose of providing a pluralityof relative angular positions of the housing 28 in relation to thesleeve 32. In this fashion, the handle can be positioned at the desiredangular position at assembly.

Sleeve 32 is provided with a pair of oppositely located angularlydirected slots indicated at 36 and these slots receive a cross pin 38,which pin extends through the interior sleeve 20 and also through acentral plunger 40. When sleeve 32 is moved angularly, the pin movesaxially by a camming action caused by slots 36, thus moving the plunger40 with it; and the plunger 40 bears on the push button 12, thusdepressing the latter. The sleeve 32 is provided with vertical slots 42receiving the pin 38 and allowing the same to move up and down withrespect thereto.

The bracket 10 is assumed to be fixed to a support such as a machineframe or housing, not shown, in the usual and conventional applicationof any switch to any use. The casing 14 being fixed to the fixed bracket10 is in turn fixed, and the nut 18 is turned upon the casing 14, sothat this nut is also fixed. The sleeve 20 being fixed to or integralwith nut 18, as above stated, is likewise fixed, while exterior housing28 and sleeve 32 may be turned on a vertical axis as far as permitted bythe relative motion of slots 36 limited by rotationally fixed pin 38.Pin 38 can move vertically in slots 42, and thus also moves plunger 40and plunger 12, the latter having the spring 16 to return the plungersupwardly.

A coil spring 44 may be used in some cases and surrounds the innermostshell 20, being located interiorly of shell 32.

When this spring is furnished, its function is to center the operatinghandle in the mid-position of its travel. This spring (and washer) cantravel only half the strokelength of the device, at which point furthertravel is restricted by a shoulder on the body 18. Since this spring 44-is stronger than spring 16, it can overcome spring 16 to the extent ofits travel, thereby centering the handle and stopping the contactsmid-way with all poles open. Any movement of the handle in eitherdirection is opposed by one spring or the other and thereby the handleis returned to the center position.

This invention provides an extremely evenly and smoothly operable deviceand one which an operator may utilize for long periods of time withoutfatigue. At the same time, the operator exercises much more constant andeven control of the push button, so that he is enabled to work itexactly as required by the machine or the operation that it is engagedupon.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

1. An attachment for operating a push button or the like having ahousing and a spring, comprising means to mount the attachment on thepush button housing, a plunger to contact and depress the push button,means to restrict the plunger to a rectilinear motion, said meansincluding a pin on the plunger and a sleeve fixed with relation to thehousing, said sleeve having a longitudinal slot receiving the pin,another sleeve, a cam slot angularly disposed in the second-namedsleeve, said pin extending into the cam slot, means to angularly movethe secondnamed sleeve, and a spring normally urging the plunger towardthe push button and opposing the push button spring.

2. The attachment of claim 1 wherein the two springs balance so that thepush button stays where positioned by the plunger.

3. The attachment of claim 1 wherein the plunger spring is weaker thanthe push button spring.

UNITED STATES PATENTS Coldwell Sept. 5, 1893 Nygren Nov. 11, 1913 HooperIan. 9, 1917 De Reamer Oct. 22, 1918 Lightfoot Oct. 14, 1952 Morton Mar.30, 1954 Lahti June 8, 1954 Weber et al Aug. 10, 1954 FOREIGN PATENTSFrance July 2, 1934 (Addition to 755,967) Switzerland Jan. 4, 1943France Aug. 17, 1926 France Jan. 24, 1935

